Various techniques for electrostatic image transfer are known. One method includes the use of an intermediate transfer member. A liquid image, which includes a liquid carrier having ink particles dispersed therein, is transferred to a photoconductive member or drum and from there to a surface (e.g., a release layer or blanket) of the intermediate transfer member. The liquid image is attracted from the photoconductive surface to the surface of the intermediate transfer member. The liquid carrier is removed from the surface of the intermediate transfer member and the ink particles are compacted on the surface in the image configuration. Thereafter, the ink particles are transferred from the surface of the intermediate transfer member to a substrate in the image configuration.
Modern liquid toner electrostatic imaging began with the invention of a new class of toners referred to as ElectroInk™. This type of toner is characterized by its toner particles being dispersed in a carrier liquid, where the toner particles include a core of a polymer with fibrous extensions extending from the core. When the toner particles are dispersed in the carrier liquid in a low concentration, the particles remain separate. Although not intending to be bound by theory, when the toner develops an electrostatic image, the concentration of toner particles increases and the fibrous extensions interlock. A large number of patents and patent applications are directed toward this type of toner (e.g., U.S. Pat. Nos. 4,794,651; 4,842,974; 5,047,306; 5,407,307; 5,192,638; 5,208,130; 5,225,306; 5,264,312; 5,266,435; 5,286,593; 5,300,390; 5,346,796; 5,407,771; 5,554,476; 5,655,194; 5,792,584 and 5,5923,929 and PCT Patent publication WO/92/17823, the entire disclosures of all of which are incorporated herein by reference).
It has been discovered that this type of toner allows for high quality offset printing quality at high speed. This type of printing is described the following U.S. Pat. Nos. 4,678,317; 4,860,924; 4,980,259; 4,985,732; 5,028,964; 5,034,778; 5,047,808; 5,078,504; 5,117,263; 5,148,222; 5,157,238; 5,166,734; 5,208,130; 5,231,454; 5,255,058; 5,266,435; 5,268,687; 5,270,776; 5,276,492; 5,278,615; 5,280,326; 5,286,948; 5,289,238; 5,315,321; 5,335,054; 5,337,131; 5,376,491; 5,380,611; 5,426,491; 5,436,706; 5,497,222; 5,508,790; 5,527,652; 5,552,875; 5,555,185; 5,557,376; 5,558,970; and 5,570,193; the entire disclosures of which are incorporated herein by reference.